JPH0340111B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for preventing corrosion of a container of a small fire extinguisher containing halon as a fire extinguishing agent. Fire extinguishers that use halon (dibromotetrafluoroethane (commonly known as Halon 2402), bromotrifluoromethane (commonly known as Halon 1301), and bromochlorodifluoromethane (commonly known as Halon 1211)) have traditionally been subject to various standards and conditions stipulated by the Fire Service Act. There is.
Halon filled in an aerosol can-type container was not approved as a fire extinguisher, as it did not meet the standards stipulated by the Fire Service Act. However, recently, public and private institutions have discovered that small fire extinguishers made by filling an aerosol can with halon are extremely effective in initially extinguishing a misfire in homes, cars, camps, etc. It has been confirmed that it will soon be recognized as an initial extinguishing agent or device. For several years, the inventor of the present application has confirmed that this type of fire extinguisher is effective for early extinguishing, and has conducted intensive research into its formulation. The biggest problem among them was that if a regular aerosol can filled with halon was stored for a long period of time, the container would corrode. The cause of this is that when a fire extinguisher is made by filling an aerosol can with halon, the halon decomposes in the presence of a small amount of moisture or air, producing corrosive substances that can be used in thin-walled tin containers or aluminum containers. It was found that light metal containers corroded during storage and were completely useless in case of emergency. Current aerosol containers are tin cans with 0.21~
Aluminum cans have a wall thickness of 0.3 mm, and aluminum cans have a wall thickness of 0.21 to 0.6 mm, but due to a legal amendment in September last year, this minimum wall thickness regulation was abolished. It is certain that the wall thickness will be reduced in the economically most advantageous direction within the range that provides the necessary withstand pressure, and it goes without saying that corrosion becomes even more of a problem when filled with halon. The present invention was completed as a result of intensive research aimed at improving the above-mentioned drawbacks. That is, the present invention uses Halon 2402 and Halon in an aerosol container made of steel or light metal with a wall thickness of less than 0.8 mm, specifically made of tin or aluminum.
1301, or those filled with Halon 1211 and Halon 1301, where the so-called extinguishing agent is Halon,
Or not limited to the above extinguishing agents, mixtures of halon and fluorocarbons, mixtures of halon and inorganic extinguishing agents,
A mixture of halon and inorganic or organic powder, a mixture of halon and compressed gas (carbon dioxide, nitrogen, laughing gas, etc.), or a mixture of two or more of the above-mentioned substances, In order to prevent the corrosion of the container that occurs when containing halon, the inventors have discovered that the above-mentioned corrosion of the container can be prevented by coexisting a super absorbent polymer in the container, leading to the completion of the present invention. This super absorbent polymer has the ability to hold water tens to hundreds of times its own weight, and these include, for example, saponified starch-polyacrylonitrile graft copolymers, starch-polymethacrylic Saponified products of nitrile graft copolymers, starch-polyacrylic acid (and its salts) graft copolymers (and crosslinked products), hydrolysates of starch-polyacrylic acid ester graft copolymers, starch-polymethacrylic acid Examples include hydrolyzates of ester graft copolymers. Instead of starch, starch derivatives such as hydroxyethyl starch and oxidized starch, cellulose derivatives such as cellulose, methylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose, or polysaccharides having hydroxyl groups can also be used. Other super absorbent polymers include polyvinyl alcohol-polyacrylic acid graft copolymers, polyacrylic acid crosslinked products, polyacrylic acid self-crosslinked products, reaction products (and salts) of polyvinyl alcohol and maleic anhydride, Examples include polyvinyl alcohol sulfonate. Most of the above-mentioned superabsorbent polymers that can be applied to the present invention also have the property of being freely processable into spherical, crushed, powder, film, or fibrous forms, so that the aerosol can-type small fire extinguisher according to the present invention Various methods can be considered for coexisting with a fire extinguisher. The purpose of the present invention is to
A small aerosol can type fire extinguisher filled with 500g or less of extinguishing agent, etc., which requires halon to be one of the constituents of the contents. Although it is a container corrosion protection, the purpose of the fire extinguisher is However, this is for extinguishing a fire, and it is not the intention of the present invention to undermine this purpose. It must be added in a form that has an anticorrosive effect without reducing fire extinguishing ability. For example, the super absorbent polymer powder or granules used in the present invention may be placed in a non-woven bag, or the powder or granules may be encapsulated as fine powder to the extent that it does not clog the valve or radiation button, or
There is a method of forming the valve into a deep tube and sealing it in a container. The above-mentioned superabsorbent polymer that can be used in the present invention has chemical water absorption and water retention abilities, but these functions are not limited to conventional physical water absorption and water retention.
Inorganic desiccant with adsorption capacity, such as silica gel,
It is completely different from activated zeolite. In this way, chemical water absorption and water retention capabilities suppress the increase in moisture inside the container, and in addition, it prevents corrosion and pitting of the container by preventing the decomposition of halon, which is a component of the contents, and suppressing the generation of corrosive substances. By doing so, we will have reliable fire extinguishing ability in the event of an emergency, and
The major objective is to reduce the damage caused by approximately 60,000 fires and approximately 2,000 deaths each year in our country, as well as the fact that this corrosion prevention method is extremely important both socially and economically. The present invention was completed by confirming the following. Various natural increases in water are known in aerosols that do not contain water, and the same is true for small aerosol can-type fire extinguishers that contain halon. In most cases, this moisture mainly enters the container through the valve part. In addition, there are cases where the contents to be filled have a high moisture content. For example, JP-A-57-
Surfactants are used when inorganic fine powder is dispersed in halon as shown in 75667, but since the water content of surfactants is very high, it is extremely difficult to use in such formulations. Halon becomes unstable and corrodes severely. It has also been found that very good results can be obtained by coexisting the superabsorbent polymer of the present invention in such a system. The amount of super absorbent polymer used in the present invention added to the small aerosol can-type fire extinguisher is effective if it is 0.1% or more based on the content, but from an economical and long-term effect perspective, it should be 0.4% or more. The most preferable amount is about 3%. Next, some embodiments of the present invention will be shown. Example 1 3 g of polyvinyl alcohol-polyacrylic acid graft copolymer powder was placed in a non-woven bag, 392 g of Halon 2402, and 85 g of Halon 1301 were placed in a tin aerosol can to make an aerosol can-shaped small fire extinguisher valve. and equipped with a radiation button.
A small fire extinguisher containing 480g was obtained. Example 2 2 g of crushed grains of starch-polyacrylic acid graft copolymer were placed in a non-woven fabric bag, which was fixed by welding to the deep tube of a valve, and 50 g of Halon 1301,
438 g of Halon 1211 was placed in an aluminum aerosol can, and a valve and emitting button were attached using a conventional method to obtain a small fire extinguisher containing 490 g. Example 3 4 g fine powder of saponified starch-polyacrylonitrile graft copolymer, Halon 2402 320
g, Halon 1301 was placed in a 76g tin aerosol can, and a small aerosol can-type fire extinguisher containing 400g was obtained by a conventional method. Example 4 40 g of Halon 1301, 379 g of Halon 1211, 25 g of fine sodium bicarbonate powder, 2.5 g of fine powder of saponified hydroxyethyl cellulose-polymethacrylonitrile graft copolymer, and 3.5 g of polyoxyethylene alkyl phenyl ether were added to aluminum. 450g by conventional method in a manufactured aerosol container
I got a small aerosol can type fire extinguisher. Next, some of the experimental results that led to the present invention will be shown.

【table】

【table】

[Table] As is clear from the above table, the effects of super absorbent polymers are very excellent. It can be said that this substance is essential for the long-term stability of small-sized fire extinguishers.

Claims (1)

[Claims] 1 Made of steel or light metal with a wall thickness of less than 0.8 mm, filled with 500 g or less of a fire extinguishing agent containing one or more selected from dibromotetrafluoroethane, bromotrifluoromethane, and bromochlorodifluoromethane. A method for preventing corrosion of small fire extinguisher containers, which is characterized by coexisting a highly water-absorbing polymer in the container of the small fire extinguisher.